Why does Biodiversity vary so much between different scales?
Biodiversity can be defined in three different ways, such as genetic diversity, the number of different species and the range of different ecosystems within an area. Biodiversity is not spread evenly throughout the earth due to global factors, regional factors and local factors that affect biodiversity and cause it to be varied on such different scales. Human influences are also not to be forgotten. The overall consensus is that humans have a negative impact on biodiversity, and later in this report I will show why that is not always the case.
The global factors that affect how biodiverse areas are are the size of the area, the age of the area, the isolation, the altitude and the position of the area on the earth and its climate. The last factor is the most important. For example the tropics are very biodiverse because they are situated at the lower latitudes. This means that the suns rays are more concentrated, making it more humid and warmer and so it has ideal conditions and so has a range of species, making it biodiverse. For example, in the polar regions it is too cold and so only certain animals are adapted to survive, thereby lowering the biodiversity. Generally, the larger an area the more biodiverse because a large continuos biomes supports a wider range of species and it encourages migration. Furthermore, the older the ecosystem the more biodiverse and if the area is isolated it will be less biodiverse but will have more endemic species. The last factor hat affects the global distribution of hazard hotspots is the altitude. The higher the altitude the less biodiversity.for example in the tropics at the base of the mountains there is a high species richness, but at the peak, because of the tundra like climate, there is low biodiversity.
As well as global factors, regional and local factors can